Pen-based devices are receiving increasing acceptance in the market by people who want to digitally record their handwritten notes. There are many environments in which the digital recording of handwritten notes is useful. For example, a pen-based device may be used by a secretary to record minutes of a meeting, by medical personnel to record a summary of a patient's condition, by a student to record class notes, and so on. These pen-based devices include tablet PCs, personal digital assistants (“PDAs”), digital tablets, and so on.
Although handwritten notes may be recorded on paper and then scanned to produce digital recordings, the digital recording of handwriting that is contemporaneous with the generation of the handwriting has several advantages. One advantage is that the contemporaneous digital recording allows the handwritten document to be immediately available for transmission (e.g., via electronic mail) to others. Another advantage is that the contemporaneous digital recording facilitates the recognition of the handwriting. A pen-based device may also record the timing and directional information of the handwriting as it is digitally recorded, which can be used to improve handwriting recognition.
When people generate handwritten notes, the notes may appear less than perfect for several reasons. One reason is that it is common for people to make an error and then try to correct that error. For example, a person may omit a letter in a word and then try to insert that letter back into the word at a later time by squeezing it between two existing letters of the word. Another reason is that people often overwrite a letter or word, which adversely affects the clarity of the handwriting. Another reason is that two letters may overlap because of carelessness of the writer, which makes the handwriting appear sloppy and difficult to read. These reasons may also make the automatic recognition of handwritten notes more difficult. In addition, handwriting recognition may be more difficult for other reasons. For example, some people may be sloppy in their placement and forming of dots (e.g., in a “j”) and bars (e.g., across an “H” or “tt”).